On Tue, Aug 11, 2020 at 10:50:28AM +0200, Jakub Jelinek via Gcc-patches wrote:
> Hi!
>
> As the testcase shows, we would ICE if the type of the first argument of
> various atomic builtins was pointer to (non-void) incomplete type, we would
> assume that TYPE_SIZE_UNIT must be non-NULL. This patch diagnoses it
> instead. And also changes the TREE_CODE != INTEGER_CST check to
> !tree_fits_uhwi_p, as we use tree_to_uhwi after this and at least in theory
> the int could be too large and not fit.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
> 2020-08-10 Jakub Jelinek <ja...@redhat.com>
>
> PR c/96545
> * c-common.c (get_atomic_generic_size): Require that first argument's
> type points to a complete type and use tree_fits_uhwi_p instead of
> just INTEGER_CST TREE_CODE check for the TYPE_SIZE_UNIT.
>
> * c-c++-common/pr96545.c: New test.
>
> --- gcc/c-family/c-common.c.jj 2020-07-31 23:07:00.566153515 +0200
> +++ gcc/c-family/c-common.c 2020-08-10 12:03:35.236841534 +0200
> @@ -7017,8 +7017,15 @@ get_atomic_generic_size (location_t loc,
> return 0;
> }
>
> + if (!COMPLETE_TYPE_P (TREE_TYPE (type_0)))
> + {
> + error_at (loc, "argument 1 of %qE must be a pointer to a complete
> type",
> + function);
> + return 0;
> + }
> +
> /* Types must be compile time constant sizes. */
> - if (TREE_CODE ((TYPE_SIZE_UNIT (TREE_TYPE (type_0)))) != INTEGER_CST)
> + if (!tree_fits_uhwi_p ((TYPE_SIZE_UNIT (TREE_TYPE (type_0)))))
> {
> error_at (loc,
> "argument 1 of %qE must be a pointer to a constant size type",
> --- gcc/testsuite/c-c++-common/pr96545.c.jj 2020-08-10 12:28:43.296222401
> +0200
> +++ gcc/testsuite/c-c++-common/pr96545.c 2020-08-10 12:28:28.258428487
> +0200
> @@ -0,0 +1,31 @@
> +/* PR c/96545 */
> +/* { dg-do compile } */
> +
> +extern char x[], y[], z[];
> +struct S;
> +extern struct S s, t, u;
> +int v, w;
> +
> +void
> +foo (void)
> +{
> + __atomic_exchange (&x, &y, &z, 0); /* { dg-error "must be a pointer to a
> complete type" } */
> +}
> +
> +void
> +bar (void)
> +{
> + __atomic_exchange (&s, &t, &u, 0); /* { dg-error "must be a pointer to a
> complete type" } */
> +}
> +
> +void
> +baz (void)
> +{
> + __atomic_exchange (&v, &t, &w, 0); /* { dg-error "size mismatch in
> argument 2 of" } */
> +}
> +
> +void
> +qux (void)
> +{
> + __atomic_exchange (&v, &w, &t, 0); /* { dg-error "size mismatch in
> argument 3 of" } */
> +}
>
> Jakub
>
Marek
